Michael Sheehan (famous Ferrari broker) has reported having seen the same number (can't remember but let's say #2 out of 448) on 3 different Barchettas. It looks very likely that more than 448 were produced (although not too many more).
Onno
Same is true of Fioranos.
Ferrari says 400 Enzos produced. Gerald Roush of Ferrari market letter says he has 440 VINS.
I know a very reliable source that says he laid eyes on more FXX's at Maranello than Ferrari says they built.
I have proof in the form of original factory documents that 360 motors do not make 400 HP.
Ferrari numbers have never been reliable.